CONCEPT ESSAYS:
 1992:      L. PETERSON/AP BIOLOGY

  Biological recognition is important in many processes at the molecular, cellular,
 and organismal levels. Select three of the following, and for each of the three that
you have chosen, explain how the process of recognition occurs and give an 
 example.
  a.    Organisms recognize others as members of their own species.
  b.    Neurotransmitters are recognized in the synapse.
  c.    Antigens trigger antibody responses.
  d.    Nucleic acids are complementary.
  e.    Target cells respond to specific hormones.

1992:      L.PETERSON/AP BIOLOGY

 Survival depends on the ability of an organism to respond to changes in its 
 environment. Some plants flower in response to changes in day length. Some
 mammals may run or fight when frightened. For both of these examples,
 describe the physiological mechanisms involved in the response.

1995:       L. PETERSON/AP BIOLOGY

Angiosperms (flowering plants) and vertebrates obtain nutrients from their environment in different ways:

(A)   Discuss the type of nutrition and the nutritional requirements of angiosperms and  vertebrates.

(B)       Describe 2 structural adaptations in angiosperms for obtaining nutrients from the  environment. Relate structure to function.

(C)       Interdependence in nature is evident in symbiosis. Explain two symbiotic relationships  that aid in nutrient uptake, using examples from angiosperms and/or vertebrates. 
 (Both examples may be angiosperms, both may be vertebrates, or one may be from  each group.)

1993:       L. PETERSON/AP BIOLOGY

 Membranes are important structural features of cells.
    (a) Describe how membrane structure is related to the transport 
           of materials across a membrane.
    (b) Describe the role of membranes in the synthesis of ATP in either
           respiration or photosynthesis.

1994:       L. PETERSON/AP BIOLOGY

Discuss how cellular structures, including the plasma membrane, specialized endoplasmic reticulum, cytoskeletal elements, and mitochondria, function together in the contraction of skeletal muscle cells.

1995:       L. PETERSON/AP BIOLOGY

The problems of survival of animals on land are very different from those of survivial of animals in an aquatic environment. Describe four problems associated with animal survival in terrestrial environments but not in aquatic environments. For each problem, explain an evolutionary solution.
 
 

     HUMAN SYSTEMS 1993    
            Many physiological changes occur during exercise.

               (a)  Design a controlled experiment to test the hypothesis that an exercise
                       session causes short-term increases in heart rate and breathing rate
                       in humans.

               (b)  Explain how at least three organ systems are affected by this increased
                       physical activity and discuss interactions among these systems.